With recent advances in digital technology, electronic devices such as portable information devices and home information appliances have been developed to provide higher functionality. Development of further miniaturized and higher-speed semiconductor elements is progressing at a high pace as electronic devices continue to be developed with higher functionality. In particular, the use of large-capacity nonvolatile memories, typified by flash memory, is expanding at a rapid pace. Furthermore, variable resistance nonvolatile memory devices using variable resistance elements are being researched and developed as the next-generation of nonvolatile memory having the potential to replace flash memory. As defined herein, a variable resistance element refers to an element which possesses certain properties allowing a resistance value thereof to change reversibly in response to an electric signal, and which is further capable of storing information corresponding to a resistance value in a nonvolatile manner.
Crosspoint nonvolatile memory devices (crosspoint memory) have been proposed as an example of large-capacity nonvolatile memory which incorporates these variable resistance elements. For example, Patent Literature 1 (PTL 1) discloses a nonvolatile memory device which includes a variable resistance film as the storage unit and a diode element as the switching element.